1. Field of the Invention
The present invention relates to a culture apparatus.
2. Description of the Related Art
In a culture apparatus, temperature and gas concentration of carbon dioxide (CO2), oxygen (O2) and the like within the culture chamber is maintained constant, and the inside of the culture chamber is kept in an aseptic state, so that culture such as a cell, and a microorganism is cultured. In such a culture apparatus, the gas concentration in the culture chamber is detected by a sensor, and gas supply into the culture chamber is controlled so that the gas concentration is maintained constant. In general, when the gas concentration in the culture chamber is detected, atmospheric gas (hereinafter referred to simply as gas) consisting principally of air in the culture chamber is sucked into piping connected to the outside of the culture apparatus, concentration of the sucked gas is detected, and then, the gas is returned into the culture chamber. In order to suck the gas from the culture chamber into the piping and to return it into the culture chamber again, a suction device such as a pump and a fan is used (See Japanese Patent Laid-Open Publication No. 2007-259715, for example).
By using the suction device as such, the gas in the culture chamber can be forcedly led to the piping and at the same time, a flow velocity of the gas in the piping can be controlled to a velocity suitable for detection by the sensor. However, since the suction device is required, a cost and power consumption are increased by that portion, as well as if the suction device fails to operate properly, the gas concentration cannot be detected accurately, and it becomes difficult to maintain the gas concentration in the culture chamber constant.